Burner and method of making the same



May 23, 1933- H. w. LE Bou'rlLLlER Er AL I 1,910,020

BURNER AND METHOD oF MAKING THE SAME Filed June 3o, 1928 i ATTORNEYS.

Patented May 23, 1933 p UNITED STATES .PATENT OFFICE HENRY W. LE BOUTILLIER, O F DREXEL IEIIIJ, AND FRED HESS, 0F PHILADELPHIA.,

PENNSYLVANIA, OE PHILADELPHIA, PENNSYLVANIA, A

ASSIGNORS, BY MESNE ASSIGNMENTS, T0 THE SELAS COMPANY,

CORPORATION 0F PENNSYLVANIA BURNER AND METHOD OF AMAKING THE SAME Application 1ed J'une 30,

The present invention relates to burners for burning pre-mixed air and combustible gas andparticularly to burners of the sieve cap type, i. e., burners having a metallic their outer end forming a multiplicity of discharge passages.

The object of our present invention is to provide an improved construction of a sieve cap burner which is characterized by its low cost of manufacture, low gas resistance and improved provisions for preventin back fire and securing the burner in place. further object of our invention is to provide an improved form of metallic burner screen and method of making the same..

- The various features of novelty which characterize our invention are pointed out with particularity in the claims annexed to and forming a part of this specification'. For a better understanding of the invention, however, and the advantages possessed by it reference should be had to the accompanying drawing and descriptive matter in which we have illustrated and described preferre embodiments of the invention. p Y Of the drafwing Fig. 1 is a plan view; and

Fig. 2 is an elevation of the assembled burner; v

Fig. 3 is anl elevation of the corrugated metal strip;

Fig. 4 is a plan view of the strip; y

Fig. 5 is an elevation of the strip as bent for insertion in the burner body; and

Fig. 6 is an elevation of a modified form of burner.

In the drawing and particularly in Figs. 1 and 2 we have illustrated a preferred embodiment of our invention in which a gas burner comprising a tubular body A of any desired diameter is provided with a counterbored portion A atone end as shown in' dotted lines in Fig. 2. A metal screen B ,constructed in the manner hereinafter de- 192s. serial No. 289,574.

1y to retain the screen in position in the counterbored portion.

The burner screen B consists of a strip of metal having corrugations extending at an oblique angle to the top and .bottom edges of the strip, and folded along its length with the corrugations of adjacent faces of the sections .at an angle Ato one another. When the burner body top portion is circular in cross-section, which' is the most advantageous form, thev screen strip is folded at unequally spaced points along 'its length with the middlesections of greater length than the end sections, so that when the folded sections `are compressed the screen will substantially conform to the burner cross-section. l

Our improved method of making a screen of this type consists in passing a metal ribbon C of relatively small width between a 70 pair of rollers which corrugate the metal in the form shown in Fig. 3. The corrugationsv `C as shown extend at an vangle tothe longitudinal axis of the strip. The overall thickness of the strip is substantially increased by the corrugating operation. In one size of burner in use the blank vstrip is three-sixteenths of an inch wide and eight-one thousandths of an inch in thickness. On being corrugated theoverall thickness is approximately one-thirty second of an inch. It is c understood, of course, that the above figures are by way of example and not of limitation. p

The corrugated stripv is then passed through a second pair of rollers, one of which is formed with a set of teeth in its periphery. The teeth are arranged in pairs with the teethvof each'pair 'in spaced alignment. The separate pairs of teeth are unequally spaced about the roll circumference so that the upper and lower edge portions of the strip are weakened by indentations C2 at unequally spaced points as shown by the dotted lines in Fig. 3. The length of strip required for/each burner screen having beenpdetermined, the 95 toothed roller'is provided 'with a tooth extending'across .the full width of the strip and so ypositioned on the periphery of the, roller that a full width indentation is made in the strip at certain points corresponding to 100 the desired strip length. The portion of the strip between two of these points is divided into indented sections, the length of which increases toward the center of the section for a burner opening of circular cross section.

The spacing of the indentations C2 can be varied for burners of d1lfercnt size and crossy sections.

The marking operation can be advantageously performed in many cases by a punch tool' having teeth spaced at the propel' distances or by a single punch operated by a suitably shaped Cam.

TheI strip is then broken into the length defined by the full width indentations and each -length is folded at the weakened points having a multiplicity of inclined channels,

'each of which has a cross-section corresponding to the size of the corrugations.

The lower portion Aa ofthe burner body may be threaded for engagement with the pipe or other container in which it is to be used. Preferably, however, the lower portion is beveled toward its end and knurled with a line knurl E substantially as'shown n Fig. 2.

The burner of our invention isparticularly' characterized by its low cost of manufacture, the effectiveness of the structure, and the ease with which it may be installed. Oxidation of resistant to oxidation.v

the metal used in the screen is one of the main operating problems of burners of this type. The screen of the present construction is made of a metal suitably resistant to oxida-v tion, such as Monel metal or pure nickel. The burner body when used under ordinary operating conditions'is formed from steel or iron pipe. Under extreme conditions the body may be also made of a metal highly The manufacturing operations are few and require relatively unskilled labor. The screen. construction described is especially efl'ective in-preventing back fire of the combustible mixture in the burner.' =-.'-Former constructions for eliminating back fire have resulted in burners-liaving an undesirably high back pressure. The present arrangement of the screen passages, however,

When the burners are knurled it is only neces# provides avery low gas resistance in the screen and a mmlmum back pressure sary to drill the burner openings in the pipe or container surface and to drive the burners into the corresponding openings. This construction provides a rela-tively permanent gas-tight connection and eliminates the numerous threading operations which are relatively expensive when performed in the field.

In the modifications illustrated in Fig.' 6, the burner body A' is provided with a plurality of screens in the eounterbored section A at the upper end of the burner. The screens are arranged in superposed relation and the gas passages in one of the screens are made of a different cross sectional area than those of the other, although it may be advantageous in some cases to provide Lscreens having the same size passages. The

construction shown is particularly adapted for use in installations wherein matter accumulates on the top of the burner and the' screen gas passages would be quickly clogged and the burner rendered inoperative unless the passages are of`suflicient size to render cleaning easy. As shown the upper screen F is made with relatively coarse corrugations and the lower screenG with relatively fine corrugations. The u'pper gas passages are therefore of greater cross-sectional area than the lower pass'aes. With the present arrangement of a c arse screen and fine screen, back fire is prevented by the line screen while an eiiicient gas iow' is maintained under all conditions. In this form the lower portion of the burner body is shown as threaded, although itcan be knurled as shown in Fig. 2.

While in accordance withA the provisions of the statutes,'we have illustrated and described the best form of embodiment of our invention now known to us, ent to those skilled in the art that changes may be made in the form of the article disclosed and the method of making the same it will be apparwithout departing from the 'spirit of our invention as set forth ,in the appended claims and that in some cases certain features of. our invention may be used to advantage without a corresponding use of other features.

Having now described'our invention what we claim as new and desire to secure by Letters Patent, is:

'1. A, gas burnercomprising a gas container having an opening therein and a screen consisting of a strip of metal having a multiplicity of inclinedcorrugations and folded along .its length to form a plurality ofside by side integrally connected sections and mounted in said opening.

l 2. A gas burner comprising a 'tubular body having a eounterbored end. portion', a .screen consisting of a strip of obliquely corrugated metal folded along its length in said counterbored portion, and the adjacent end of said body being spun over to retainv said screen in position.

4. A gas burner comprising a tubular bodyI having one end counterbored, and a screen in sald counterbored portion conslstmg of a strip of metal having inclined corrugations therein and folded along its length.

5. A fire screen for a gaseous fuel system comprising a strip of imperforate metal folded along its length into a plurality of juxtaposed integrally connected portions, the adjacent faces of each pair of juxtaposed portions being arranged to form a plurality ofgas passages parallel to planes of -said portions.

6. A fire" screen for a gaseous fuel system comprising a strip of metal having inclined corrugations therein and folded along its length into a plurality of integrally connected contacting sections with the corrugations of each pair of contacting faces at an angle to one another.

7. A ire screen for a gaseous fuel system comprising a strip of metal having inclined corrugations therein and bent along its length into a plurality of sections, the sections increasing in length towards the middle of the strip, and the corrugations of each pair of contacting faces being at an angle to one' 8. An article of manufactureconsisting of a thin stripof metalhaving corrugations extending at an oblique -angle tothe length of said strip, said strip being weakened at spaced points along its length and arranged to be folded at said weakened points.

9. The method of making a fire screen for a gaseous fuel system which comprises corrugating an elongated strip of metal, and arranging each strip so formed intoa plurality of integrally connected contacting sections Y with the corrugations of each section angularly displaced relative to the corrugations of the section Contactin therewith.

10. The method o making a fire screen for a gaseous fuel system whichcomprises corrugating an elongated strip of metalwith the corrugations inclined at an angle to the side edge portions and folding the strip along its length into a .plurality of portions of -unequal length with the corrugations of ad'- jacent portions at an angle to one another.

screen is facilitated and back fire is minimized. y v 0,12. A gas burner comprising a body portion having a longitudinal passage for a combustible gas therein, and a plurality of screens in superposed relation in said passage, each of said screens being formed of a folded strip of corrugated metal, the corrugations in the lower of said screens being liner than the corrugations in the upper of said screens.

1.3. A gas burner comprising a body portion having la passage for a combustible gas therein and a plurality of screens arranged in series in the discharge end of said passage and having a multiplicity of gas passages formed therein, the gas passages in the inner screen being of smaller cross section than the passages in the outer screen, andlone of said screens being formed by an elongated strip of metal having a plurality of inclined corrugations and folded alongits length into a plurality of'pairs of contacting sections. 14. A gas burner lcomprising a body portion having a passage for a combustible gas therein and a-plurality of screens arranged in series in the discharge end of said passage and having a multiplicity ofgas passages vformed therein, each of said screens being forlned by an elongated strip` of metal having a plurality of inclined corrugations andclined corrugations in a portion of its width,

said strip being folded along vits length into la. plurality of pairs of integrally connected 11. A gas burner comp-rising a tubular` body having an axial passage for a. combustible gas therein, and a plurality of burner screens located in the discharge end of said passage in a series relation the gas passages in the outerA screen being substantially larger in cross-section than the passages in thefin-v ner screen, whereby cleaning of the outer contacting sections, the corrugations of each pair ofcontacting sections being angularly displaced.

16. A fire screen for a gaseous fuel system comprising an elongated strip of material of relatively narrow width having ay multiplicity of inclined' corrugations in a portion of its width, said strip being folded along its length into a. plurality of pairs of integrally connected contacting sections, the' corrugations of each pair of contacting sections be-4 ing angularly displaced sufficiently to prevent nesting of the corrugations of contacting surfaces.

17. The method of making a iire screen vfor a gaseous fuel system which comprises forming a multiplicity of inclined corrugations in anl elongated strip of thin material of relatively. narrow width and folding the strip along its length into a plurality ofpairs ofl integrally 'connected contacting sections with the corrugations of each pair oi' contacting i sections arranged at an angle to one another. 18. The method of making a fire screen for a gaseous fuel system which comprises forming a multiplicity of inclined corrugations in an elongated strip of thin metal of relatively narrow width, Weakeningthe strip at a plurality of predetermined points along its length and folding the strip along its length at the weakened points into a plurality of pairs of contacting sections with the corrugations of each pair ofcontacting sections an ularly displaced.

igned at Philadelphia, in the county of Philadelphia and State of Pennsylvania, this 28th day of June, A. D. 1928.

HENRY W. LE BOUTILLIER. FREDIESS. 

